GZIP(1) BSD General Commands Manual GZIP(1)
gzip -- compression/decompression tool using Lempel-Ziv coding (LZ77)
gzip [-cdfhlNnqrtVv] [-S suffix] file [file [...]]
gunzip [-cfhNqrtVv] [-S suffix] file [file [...]]
zcat [-fhV] file [file [...]]
The gzip program compresses and decompresses files using Lempel-Ziv coding (LZ77). If no
files are specified, gzip will compress from standard input, or decompress to standard out-
put. When in compression mode, each file will be replaced with another file with the suf-
fix, set by the -S suffix option, added, if possible. In decompression mode, each file will
be checked for existence, as will the file with the suffix added.
If invoked as gunzip then the -d option is enabled. If invoked as zcat or gzcat then both
the -c and -d options are enabled.
This version of gzip is also capable of decompressing files compressed using compress(1) or
The following options are available:
-9, --best These options change the compression level used, with the -1 option being
the fastest, with less compression, and the -9 option being the slowest,
with optimal compression. The default compression level is 6.
-c, --stdout, --to-stdout
This option specifies that output will go to the standard output stream,
leaving files intact.
-d, --decompress, --uncompress
This option selects decompression rather than compression.
-f, --force This option turns on force mode. This allows files with multiple links,
overwriting of pre-existing files, reading from or writing to a terminal,
and when combined with the -c option, allowing non-compressed data to pass
-h, --help This option prints a usage summary and exits.
-l, --list This option displays information about the file's compressed and uncom-
pressed size, ratio, uncompressed name. With the -v option, it also dis-
plays the compression method, CRC, date and time embedded in the file.
-N, --name This option causes the stored filename in the input file to be used as the
-n, --no-name This option stops the filename and timestamp from being stored in the out-
-q, --quiet With this option, no warnings or errors are printed.
-r, --recursive This option is used to gzip the files in a directory tree individually,
using the fts(3) library.
-S suffix, --suffix suffix
This option changes the default suffix from .gz to suffix.
-t, --test This option will test compressed files for integrity.
-V, --version This option prints the version of the gzip program.
-v, --verbose This option turns on verbose mode, which prints the compression ratio for
each file compressed.
If the environment variable GZIP is set, it is parsed as a white-space separated list of
options handled before any options on the command line. Options on the command line will
override anything in GZIP.
bzip2(1), compress(1), xz(1), fts(3), zlib(3)
The gzip program was originally written by Jean-loup Gailly, licensed under the GNU Public
Licence. Matthew R. Green wrote a simple front end for NetBSD 1.3 distribution media, based
on the freely re-distributable zlib library. It was enhanced to be mostly feature-compati-
ble with the original GNU gzip program for NetBSD 2.0.
This manual documents NetBSD gzip version 20040427.
This implementation of gzip was written by Matthew R. Green <firstname.lastname@example.org>.
BSD June 18, 2011 BSD